Kent Marine Pro Clear Marine Tank Clarifier, 8 oz.Pro Clear Marine Tank Clarifier produces and maintains crystal clear aquarium water without affecting pH. Whereas competing products may clog the fish s gills, suffocating them, and cause invertebrates to close up. Kent Pro Clear uses a blend of high tech polymers that will safely flocculate cloudy water causing particles. Contains no phosphates, nitrates, or silicates to cause undesirable algae or slime growths. 100% biodegradable.Directions: Dilute one drop per gallon of aquarium capacity or one teaspoon (capful or 5 ml) per 50 gallons (190 liters) of aquarium capacity in cup of water and evenly disperse around the aquarium. Precipitated particles should be removed by a properly working mechanical filter and fine filtering medium, such as filter floss, or siphoned out. Allow 8 hours before siphoning. Repeat in 24 hours, if necessary.